If you're due to have some vaccinations before your summer holidays, make sure you get a decent night's kip afterwards - it could affect whether they work or not.
Researchers, who were measuring how the immune system reacts to vaccines in real-life conditions found poor sleep can reduce the effectiveness of jabs.
Lead author Dr Aric Prather, from the University of California, San Francisco, said: 'With the emergence of our 24-hour lifestyle, longer working hours, and the rise in the use of technology, chronic sleep deprivation has become a way of life for many.
Protection: Lack of sleep may have a detrimental effect on the immune system making a vaccine less effective
'These findings should help raise awareness in the public health community about the clear connection between sleep and health.'
Previous research has shown that poor sleep can make people susceptible to illnesses such as upper respiratory infections.
In the latest study researchers looked to see if it could affect how well the immune system worked. To do this they investigated the antibody response to hepatitis B vaccinations on adults in good health.
Antibodies are manufactured by the immune system to identify and neutralise foreign objects such as viruses.
The study involved 125 people between the ages of 40 and 60. All were non-smokers in relatively good health, and all lived in Pennsylvania - the study was conducted at the University of Pittsburgh.
Each participant was administered the standard three-dose hepatitis B vaccine; the first and second dose were administered a month apart, followed by a booster dose at six months.
Antibody levels were measured prior to the second and third vaccine injection and six months after the final vaccination to determine whether participants had mounted a 'clinically protective response.'
All the participants completed sleep diaries detailing their bedtime, wake time and sleep quality, while 88 of them also wore electronic sleep monitors known as actigraphs.
The researchers found that people who slept fewer than six hours on average per night were far less likely to mount antibody responses to the vaccine. They were therefore 11.5 times more likely to be unprotected by the vaccine than people who slept more than seven hours on average.
Of the 125 participants, 18 did not receive adequate protection from the vaccine.
At least seven hours of rest is needed after having an injection
Dr Prather said: 'Sleeping fewer than six hours conferred a significant risk of being unprotected as compared with sleeping more than seven hours per night.'
He stressed that sleep plays an important role in the regulation of the immune system and a lack of sleep may have detrimental effects on the immune system that are integral to vaccine response.
Dr Prather added: 'Based on our findings and existing laboratory evidence, sleep may belong on the list of behavioural risk factors that influence vaccination efficacy.
'While there is more work to be done in this area, in time physicians and other health care professionals who administer vaccines may want to consider asking their patients about their sleep patterns, since lack of sleep may significantly affect the potency of the vaccination.'
The findings were published in the journal Sleep.
Read more: http://www.dailymail.co.uk/health/article-2182123/Getting-holiday-jabs-Why-essential-good-nights-sleep-afterwards.html#ixzz22Jr93e5U